Insurance claim against third party. their fault?

Question

My son has made a claim against another driver who knocked him off his bike.

When he renews his insurance next year will he have to report a not at fault claim and will it affect his premiums

Answer 1

he will have to report a not at fault claim and it WILL NOT affect his insurance as it wasnt his fault

Answer 2

He will have to declare it as not at fault BUT it may go up, as I was experimenting before with claims and it went up even though I put not at fault.